Identification and functional analysis of PDC-E2_159-167–specific CD8⁺ T cells in the peptide-induced CTL line. PBMCs from an HLA-A*0201⁺ PBC patient were cocultured with PDC-E2_159-167–loaded APCs for 14 days to generate a CTL line. (a) The CTL line was tested for cytotoxicity against PDC-E2_159-167 peptide– or control peptide–loaded T2 targets at different E/T ratios. HBc_18-27, an HLA-A*0201–restricted irrelevant epitope, was used as control. Displayed are the mean specific lysis of triplicate testing. (b) The CTL line was restimulated with PDC-E2_159-167 peptide or control peptide in the presence of brefeldin A, followed by intracellular staining for IFN-γ. Displayed in the dot plots are cells gated at lymphocyte population by forward scattering and side scattering and the CD4^– population. The number next to the box is the percentage of IFN-γ–producing cells in the lymphocyte population. (c) The CTL line was stained with PDC-E2_159-167 tetramer and Ab’s against CD4 and CD8, followed by flow cytometric analysis. Displayed in the dot plots are cells gated at lymphocyte population by forward scattering and side scattering and the CD4^– population. The number next to the box is the percentage of positively stained cells in the lymphocyte population.